At just over 24mm wide and featuring their deepest profile 245mm the grail is the most aerodynamic rim no tubes have ever made though it rivals much deeper designs in the wind tunnel they designed the grail to be much more than just fast in a straight line the variable wall thickness spoke bed maximizes durability and ensures consistent spoke tension while keeping weight low its internal rim channel and true bst sidewalls combine to lend additional strength and create a tyre profile that